Tracked vehicles, such as bulldozers, movable cranes, loaders, backhoes, and tanks utilize idler gears and flexible tracks. The idler gear transfers rotation to the flexible tracks as the vehicle moves from one location to another. The idler wheel is typically mounted for rotation on a fixed idler shaft which is rigidly attached to the frame of the tracked vehicle. Unfortunately, as the idler gear rotates around the fixed idler shaft it wears down the portion of the shaft that is in contact with the idler gear. In addition, the wear on the idler shaft is difficult to detect, as well as time consuming and expensive to repair.